1. Field of the Invention
The invention pertains to improvements in water treatment processes and apparatus and particularly the arrangement of the apparatus and processing equipment associated therewith. Known art can be found in class 202 subclass 175 and in class 210, subclass 73 and in other classes and subclasses.
2. Description of the Known Art
Those skilled in the art will appreciate that it is often desirable to remove entrained solids from waste water and the like. Often, processing of wastewater is slowed by the removal of these entrained solids. The known art has provided a variety of proposals to meet this need and such proposals have been attempted, and they may have been acceptable for their intended purposes. One conventional proposal is to first treat the wastewater to remove most of the entrained solids, perhaps as much as 98% of the entrained solids. After the first step, the remaining water entrained solids are substantially more viscous, and it is commonly referred to as sludge. The sludge is often next placed in a lagoon so that the remaining solids settle to the bottom over an extended period of time. Water from the tops of these lagoons is normally drawn off as the solids settle until the lagoon fills. These lagoons are often outside and exposed to the weather and climate and can release malodorous fumes. The lagoons are often rained upon and can spill uncontrollably if flooded, which is undesirable.
In the fairly recent past, such lagoon systems have become less favored and it is now necessary to address the removal of these concentrated solids from the sludge instead of simply pumping the sludge into a lagoon and waiting until the solids settle out. Proposed solutions provided in the art have been limited in their application and have failed to address large quantities of entrained solids in large volumes of wastewater that must be processed in a relatively short period of time, such as is often encountered with animal processing facilities. Such facilities often generate wastewater containing large amounts of animal portions and especially fat. These entrained solids are difficult to substantially remove from the wastewater and especially sludge in a timely manner.
Most previously proposed solutions for such problems have not provided processes and devices adept at handling large quantities of solids entrained in large volumes of water and those that have attempted this are unduely slow and inefficient or otherwise unsatisfactory. Therefore, a need exists for an improved water treatment process and apparatus and one that can successfully address the perceived shortcomings of the known art is desirable.
Known art which may be relevant to the present invention includes the following patents with their abstracts, the teachings of which are incorporated by reference.
U.S. Pat. No. 3,997,406, issued to Arvanitakis on Dec. 14, 1976, entitled Evaporating Apparatus, is for a method of and apparatus for receiving low-volume liquid sludge concentrations, exposing the liquid-sludge slurry to a heating surface thereby evaporating a portion of the liquid from the slurry, and advancing the contaminant bearing liquid for further exposure to additional heating surfaces such that as the slurry passes therethrough, in thermal contact with the heating surfaces, the solids content is increased by evaporating the liquid material while allowing the solids material to accumulate on the heating surfaces which are automatically and continuously cleaned to maintain the efficiency of the system and discharge these materials in a substantially dry state. This reference is for low volumes of wastewater treatment.
U.S. Pat. No. 4,192,746, issued to Arvanitakis on Mar. 11, 1980 is entitled Liquid Clarification System. Its abstracts describes a liquid clarification system for separating solid and/or chemical contaminants from an unclarified liquid wherein a variable influent is passed through a settling clarifier to separate a portion of the contaminants from the liquid forming a semi-solid sludge. The sludge is passed into a reservoir and delivered to a filtration system at a controlled predetermined percentage of solids material. The solids material is circulated through the filtration system to form a filter cake on the septum of filters carried in a filtration chamber and the liquid is clarified by passing through the filter cake formed thereon. Periodically when the filter cake must be reformed, the expended cake is removed from the septum and conveyed from the filtration chamber through a sludge drying system to be discharged as dry solids waste material. This reference uses a filter to remove entrained solids, which requires filter removal and cleaning.
U.S. Pat. No. 4,188,195, issued to Jablin on Feb. 12, 1980 is entitled Treatment of Waste Liquor. Its abstract describes a waste liquor treatment system comprising an evaporator in combination with a gas cooler, the evaporator providing fractional distillation of waste liquor, thereby separating the liquor into its several components of gaseous vapors, purified water and concentrated brine. Condensed liquor from the gas cooler or flushing liquor used to spray an industrial process gas in the collecting mains of the gas-producing plant provides thermal energy from its waste heat to run the evaporator. The evaporator consists of a boiler section, a condenser section, a vacuum pump, a liquor circulating pump, and nozzles for extracting the products. The gas cooler may be one or two stage. In the one stage cooler, the hot liquor which condenses in the gas cooling process or flushing liquor from the collecting mains of the gas-producing plant provides energy for the evaporator through means of a heat exchanger. In the two stage gas cooler, the hot liquor in the first stage is circulated directly to the boiler section of the evaporator. The hot liquor from the second stage is circulated through a separate heat exchanger. This reference does not handle entrained solids.
U.S. Pat. No. 3,946,495, issued to Osdor on Mar. 30, 1976 is entitled Method and Apparatus for Drying Moisture-Containing Solids Particularly Domestic Refuse and Sludge Cakes. This patent describes a method and apparatus for the production of solid fuel and steam by drying moisture-containing solids, such as refuse and sludge cakes, in a multi-stage heating zone by using the moisture-containing solids as the feed-water in a direct contact countercurrent flow pressurized boiler. After vaporizing the bulk of the moisture in the heating zone of the boiler, the solid residue is further dried in a multi-stage flashing zone. From the upper end of the heating zone is removed a nearly saturated steam including the water vapor evaporated from the moisture-contained solids by the heat of cooling of the introduced superheated steam. A portion of the removed steam equal to the vaporized moisture is heated and then directed to a turbine, generating all the power required to operate the system. The bulk of the removed steam equal to the introduced superheated steam is compressed, reheated and recycled through the heating zone. The dried solid is removed at the lower end of the flashing zone and is incinerated, and the recovered heat is utilized to supply the heat required for said drying, and to produce saturated steam for heating purposes, or superheated steam for power generation. In the latter case the heat of condensation of the turbine exhaust steam is utilized advantageously as a heat source in a distillation plant for fresh water production. This reference is directed to the burning of the solids, which are in some instances valuable commodities that can be advantageously used for other purposes if collected instead of incinerated.
U.S. Pat. No. 7,882,646, issued to Gorbell et al. on Feb. 8, 2011 is entitled Process and System for Drying and Heat Treating Materials. This patent describes systems and methods for conversion of high moisture waste materials to dry or low moisture products for recycle or reuse. The equipment systems comprise a gas turbine generator unit (preferred heat source), a dryer vessel and a processing unit, wherein the connection between the gas turbine and the dryer vessel directs substantially all the gas turbine exhaust into the dryer vessel and substantially precludes the introduction of air into the dryer vessel and wherein the processing unit forms the dried material from the dryer vessel into granules, pellets or other desired form for the final product. Optionally, the systems and methods further provide for processing ventilation air from manufacturing facilities to reduce emissions therefrom. This reference and the preceding references fail to contain potential offensive odors.
Other attempts involving filters to spin the sludge to separate water from the solids are difficult to clean and maintain or to use with high volumes of sludge. Other attempts at dehydrating the sludge have required too much energy to heat the sludge to evaporate the water or too much time to evaporate the water for use with high volumes of sludge.
Also, commercially available equipment and components may be relevant, including commercial and municipal sewage treatment systems and processes and accompanying equipment and the like. Such equipment may be used in implementing an exemplary embodiment in accordance with the present invention.
None of these references, either singly or in combination, disclose or suggest the present invention. It is desirable to have an improved water treatment process and apparatus to address the perceived shortcomings of the known art. It is desirable to produce a usable dried and separated solid product removed from the wastewater. It is desirable to substantially contain offensive odors within the treatment apparatus. It is desirable to process large quantities of wastewater to remove entrained solids therefrom in a timely manner, generally in the range of five to ten gallons of wastewater per minute.
While it is evident from past attempts that solids removal from waste water is desirable, the known art is limited in its teaching and utilization, and an improved system is needed to overcome these limitations. An improved water treatment process and accompanying apparatus should provide a simple and efficient system for meeting the various needs of field personnel. The system should enable the user to work efficiently in the field or at other remote locales as desired. The system should be adaptable to retrofit to existing locales such as animal husbandry facilities, animal processing facilities, waste processing facilities, municipal sewage facilities and the like.